Hysterectomy (surgical removal of the uterus) is performed on approximately 600,000 women annually in the United States. Hysterectomy is often the therapeutic choice for the treatment of uterine cancer, adenomyosis, menorrhagia, prolapse, dysfunctional uterine bleeding (abnormal menstrual bleeding that has no discrete anatomic explanation such as a tumor or growth), and muscular tumors of the uterus, known as leimyoma or uterine fibroids.
However, hysterectomy is a drastic treatment, having many undesirable characteristics. Thus, any method which can approximate the therapeutic result of a hysterectomy without removing the uterus would be a significant improvement in this field. Newer treatment methods have been developed for some diseases which may spare these women a hysterectomy.
In an article published in 1964, Bateman reported that uterine artery vessel ligation or division, achieved via infra-abdominal surgery similar to hysterectomy, was effective in treating menorrhagia both with and without myomectomy. Bateman, W., M.D., “Treatment of intractable menorrhagia by bilateral uterine vessel interruption”, 89 Am. J. Obstet. Gynecol. 825-827 (Harcourt Health Sciences, Jul. 15, 1964). While Bateman reported some success, this procedure involves opening the abdominal cavity, with the known attendant risks and disadvantages.
In 1995, it was demonstrated that uterine fibroids could be treated without hysterectomy using a non-surgical therapy, specifically comprising bilateral intraluminal occlusion of the uterine arteries (Ravina et al., “Arterial Embolization to Treat Uterine Myomata”, Lancet Sep. 9, 1995; Vol. 346; pp. 671-672, incorporated in its entirety herein). This technique is known as “uterine artery embolization”. In this technique, uterine arteries are accessed via a transvascular route from a common femoral artery into the left and right uterine arteries by means of an intravascular catheter and embolic material, such as small metallic coils, polyvinyl alcohol particulate and the like, is delivered through the catheter to the uterine arteries which quickly become occluded.
See also Burbank, Fred, M.D., et al, Uterine Artery Occlusion by Embolization or Surgery for the Treatment of Fibroids: A Unifying Hypothesis Transient Uterine Ischemia, The Journal of the American Association of Gynecologic Laparoscopists, November 2000, Vol. 7, No. 4 Supplement, pp. S3-S49. U.S. Pat. No. 6,254,601, to Fred Burbank et al, entitled “Methods for Occlusion of the Uterine Arteries”, describes numerous devices and methods useful for occluding a uterine artery by penetrating the tissue of the patient to access the uterine artery. The devices and methods described in Burbank '601 have been useful in occluding a uterine artery, however there have been some difficulties encountered with their use.
The uterus has a dual (or redundant) blood supply, the primary blood supply being from the bilateral uterine arteries, and the secondary blood supply from the bilateral ovarian arteries. Consequently, when both uterine arteries are occluded, i.e. bilateral vessel occlusion, the uterus and the fibroids contained within the uterus are both deprived of their blood supply. However, as demonstrated by Ravina et al. and Burbank et al., the ischemic effects on the fibroid is greater than the effect on the uterus. In most instances, the fibroid withers and ceases to cause clinical symptoms.
However, many physicians do not possess the training or equipment necessary to perform catheter-based uterine artery embolization under radiologic direction. Accordingly, there are substantially fewer uterine artery embolizations performed, worldwide, each year than hysterectomies for symptomatic uterine fibroids and other uterine disorders.
Recently, fibroid treatment procedures have been described wherein the uterine arteries are temporarily occluded by an intravaginal device which is clamped or otherwise pressed against a tissue bundle with the patient's uterine artery being within the bundle. Pressure on the tissue occludes the underlying uterine artery causing thrombus to form in the occluded artery. While these procedures have shown much promise, they typically take about six hours for completely effective treatment, which means the patient must be under observation and frequently sedated during the period.
What is needed, therefore, are intravaginal devices and procedures for using such devices which can be easily used by physicians with limited training to occlude blood flow in a female patient's uterine arteries and which reduces the period the patient's uterine arteries must be clamped.